This patent application relates generally to shock tubes. More specifically, this patent application relates to a sudden release valve for a shock tube.
In general, pneumatically triggered shock tubes were born out of the need for a light weight device to create an acoustic signature for the purpose of improvised explosive device (IED) training. A shock wave may be generated by a sudden pressurization of a sonic orifice. This sudden pressure release of gas from a finite volume plenum may be implemented by triggering a valve opening. Such valve opening creates a shock wave to generate an audible and/or visual signature. Such a signature may include a loud bang, a powder substance release and/or a flash-strobe.
Conventional shock tubes include a cylinder arrangement having a plastic diaphragm separating a low pressure carbon dioxide (CO2) gas chamber and a high pressure CO2 gas chamber. Under predetermined conditions, the diaphragm is exploded open to produce a shock wave that travels down the low pressure section of the cylinder to create a signature. This arrangement typically produces a weak signature. Further, CO2 must always be readily available to re-charge the shock tubes having this arrangement. Additionally, after activation of a shock tube using a breakable diaphragm, the cylinder arrangement is often no longer reusable and must be rebuilt or replaced.